Vehicle security systems are widely used to deter vehicle theft, prevent theft of valuables from a vehicle, deter vandalism, and to protect vehicle owners and occupants. A typical automobile security system, for example, includes a central processor or controller connected to a plurality of vehicle sensors. The sensors, for example, may detect opening of the trunk, hood, doors, windows, and also movement of the vehicle or within the vehicle. Ultrasonic and microwave motion detectors, vibration sensors, sound discriminators, differential pressure sensors, and switches may be used as sensors. In addition, radar sensors may be used to monitor the area proximate the vehicle.
The controller typically operates to give an alarm indication in the event of triggering of a vehicle sensor. The alarm indication may typically be a flashing of the lights and/or the sounding of the vehicle horn or a siren. In addition, the vehicle fuel supply and/or ignition power may be selectively disabled based upon an alarm condition.
A typical security system also includes a receiver associated with the controller that cooperates with one or more remote transmitters typically carried by the user as disclosed, for example, in U.S. Pat. No. 4,383,242 to Sassover et al. and U.S. Pat. No. 5,146,215 to Drori. The remote transmitter may be used to arm and disarm the vehicle security system or provide other remote control features from a predetermined range away from the vehicle. Also related to remote control of a vehicle function U.S. Pat. No. 5,252,966 to Lambropoulous et al. discloses a remote keyless entry system for a vehicle. The keyless entry system permits the user to remotely open the vehicle doors or open the vehicle trunk using a small handheld transmitter.
Earlier vehicle security systems needed to be directly connected by wires to individual vehicle devices, such as the vehicle horn or door switches of the vehicle. In other words, such vehicle security systems were hardwired to various vehicle components, typically by splicing into vehicle wiring harnesses or via interposing T-harnesses and connectors. A significant advance in the vehicle security industry is disclosed in U.S. Pat. No. 5,719,551 assigned to the assignee of the present invention. This patent discloses providing multi-vehicle compatibility between a vehicle security controller and a vehicle of a type including a vehicle data communications bus. Accordingly, the vehicle security or remote function controller is permitted to communicate with a vehicle device using a set of desired signals for a desired vehicle from a plurality of sets of signals for different vehicle.
As vehicle security systems have become more ubiquitous, alarm indications have become more common, especially in view of the number of false alarms. Indeed many passers-by have become immune to the sound and appearance of an activated vehicle security system. U.S. Pat. No. 6,130,605, also assigned to the assignee of the present invention, discloses an audible alarm indicator that generates an alarm as a plurality of distinguishable sound patterns. In other words, the alarm indication produced sounds as if multiple sirens are sounding. Accordingly, those in the vicinity are likely to believe that many vehicles are having their security systems breached.
Despite continuing developments in the area of vehicle security, there is still a general desirability to generate an alarm indication at the vehicle responsive to a vehicle security breach that is likely to attract the attention of those in the vicinity and encourage a would-be thief to immediately leave the vehicle.